E. J. Corey, et al disclose a conjugate addition reaction in J. Am. Chem. Soc., 94, 7210 (1972), which has been used by Paul W. Collins, et al, J. Med. Chem., 20, 1152 (1977), and H. C. Kluender, et al, Chemistry, Biochemistry and Pharmacological Activity of Prostanoids, S. M. Roberts and F. Scheinman (eds.), page 370, Pergamon Press, Oxford and New York (1979) for the synthesis of certain prostaglandins. This method, which involves the preparation of copper (I) pentyne, its solubilization in ether with hexamethylphosphoroustriamide, the reaction of the resultant solution with an alkyl lithium at -60.degree. C. to -78.degree. and finally, the addition of a substituted cyclopent-2-en-1-one also at very low temperatures is suitable for bench scale preparations, however, it requires certain reagents and conditions which are undesirable in commercial scale production. These include the use of copper (I) pentyne solubilized with hexamethylphosphoroustriamide (HMPA), ethyl ether (Et.sub.2 O) and very low temperatures (-78.degree. C.). The Kluender reference also used highly pyrophoric tert-butyllithium for generation of the alkyl lithium reagent.
For the commercial scale production of therapeutically useful prostaglandins, alternative reagents and conditions, as well as a reduction in the number of steps involved in product synthesis, would be desirable.